The ABS has published projections of the Australian population to the year 2101, based on a combination of assumptions concerning future levels of births, deaths and migration. Three main series of projections have been produced, based on differing levels of these variables.

Series I assumes an annual net overseas migration gain of 110,000, high net internal migration gains and losses for States and Territories, and a total fertility rate of 1.75 babies per woman by 2008-09, then remaining constant. Series II assumes an annual net overseas migration gain of 90,000, medium net internal migration gains and losses for States and Territories, and a total fertility rate falling to 1.6 babies per woman by 2008-09, then remaining constant. Series III assumes an annual net overseas migration gain of 70,000, generally small net internal migration gains and losses for States and Territories, and a total fertility rate falling to 1.6 births per woman in 2008-09, then remaining constant. All series assume that the 1986 to 1996 rate of improvement in life expectancy of 0.30 years per year for males and 0.22 years for females continues for the next five years and then declines gradually, resulting in life expectancy at birth of 83.3 years for males and 86.6 years for females in 2051. After this it is assumed to remain constant.

Graph 5.10 shows that Australia's population is projected to grow from 19 million in 1999 to around 19.4 million in 2001 and between 24.1 and 28.2 million in 2051. By 2101 the population is projected to rise to between 22.6 and 31.9 million. The rate of population growth is projected to vary at different times during the projection period, with a clear long-term declining trend from 1.2% in 1998-99 to between 0.0% and 0.4% by 2050-51 and to between -0.1% and 0.2% by 2100-01. The reason for this slowing in growth is mainly a projected decline in the natural increase (births minus deaths) of the population. This decline is largely a result of the increasing number of deaths occurring in a rapidly ageing population as well as the low and declining fertility.

The populations of most States and of the Territories are expected to increase over the projection period, with the largest increases projected for the Northern Territory (between 36% and 163%), followed by Queensland (between 53% and 106%) and Western Australia (between 44% and 87%) which are well above those of Australia (between 27% and 49%).

Tasmania and South Australia are the only States where the population is projected to decline under each projection series. Tasmania's population is projected to decline by between 7% and 51% by 2051, from 470,300 in 1999 to between 231,300 and 435,700 in 2051. South Australia's population is projected to be between 1,410,500 and 1,477,100 persons in 2051, a decline of between 1% and 6% from its 1999 level of 1,493,100.

These projections are summarised in table 5.11.

5.11 ACTUAL AND PROJECTED POPULATION - As at 30 June

1999

2021

2051

Capital city/balance of State

Actual

’000

Series I

’000

Series II

’000

Series III

’000

Series I

’000

Series II

’000

Series III

’000

Sydney

4,041.4

5,143.2

5,039.7

4,986.9

6,215.8

5,857.8

5,704.7

- Balance of New South Wales

2,370.3

2,696.0

2,560.7

2,493.7

2,785.8

2,390.0

2,206.0

- Total New South Wales

6,411.7

7,839.2

7,600.4

7,480.6

9,001.6

8,247.8

7,910.7

Melbourne

3,417.2

4,101.6

4,081.8

4,177.5

4,492.6

4,393.2

4,638.8

- Balance of Victoria

1,295.0

1,324.9

1,337.3

1,371.5

1,135.5

1,154.0

1,238.3

- Total Victoria

4,712.2

5,426.5

5,419.0

5,549.0

5,628.1

5,547.2

5,877.1

Brisbane

1,601.4

2,364.4

2,215.5

2,083.3

3,311.0

2,864.1

2,510.9

- Balance of Queensland

1,910.9

2,824.7

2,593.2

2,453.0

3,917.9

3,237.2

2,862.8

- Total Queensland

3,512.3

5,189.1

4,808.7

4,536.3

7,229.0

6,101.3

5,373.7

Adelaide

1,092.9

1,142.2

1,172.3

1,221.2

1,031.1

1,102.2

1,228.6

- Balance of South Australia

400.2

421.3

390.5

367.7

392.0

308.3

248.5

- Total South Australia

1,493.1

1,563.6

1,562.8

1,588.9

1,423.1

1,410.5

1,477.1

Perth

1,364.2

1,929.5

1,817.5

1,725.2

2,565.4

2,231.5

1,981.8

- Balance of Western Australia

496.8

682.6

650.7

611.0

912.3

806.3

692.7

- Total Western Australia

1,861.0

2,612.1

2,468.2

2,336.2

3,477.7

3,037.8

2,674.5

Hobart

194.2

202.0

187.1

169.0

186.7

146.2

99.7

- Balance of Tasmania

276.1

283.1

254.9

239.3

249.0

173.1

131.6

- Total Tasmania

470.3

485.2

442.0

408.3

435.7

319.3

231.3

Darwin

88.1

145.4

129.3

104.5

242.8

192.2

121.2

- Balance of Northern Territory

104.8

163.2

135.8

123.2

263.9

177.4

141.8

- Total Northern Territory

192.9

308.7

265.1

227.7

506.6

369.6

263.0

Total Australian Capital Territory

310.2

397.9

356.5

309.6

489.3

371.7

248.3

Total Capital Cities

12,109.5

15,426.1

14,999.5

14,777.3

18,534.7

17,159.0

16,533.9

Total States and Territories Balance(a)(b)

6,857.3

8,399.7

7,927.0

7,662.9

9,660.0

8,249.6

7,525.1

Total Australia(b)

18,966.8

23,825.9

22,926.4

22,440.2

28,194.7

25,408.5

24,059.0

(a) Excludes balance of ACT. (b) Includes Other Territories.

Source: Population Projections, Australia 1999 to 2051 (3222.0).

The projections show that the ageing of the population, already evident, is set to continue. The 1999 median age of 34.9 years is projected to increase to between 43.6 and 46.5 years in 2051 and to between 44.0 and 46.6 years in 2101.

The age structure of the population will change noticeably by 2101. Graph 5.12 shows a heavier concentration in the ages 50 years and over and smaller increases or slight declines in the younger ages.

The proportion of the population aged 65 years and over is expected to increase substantially, from 12% in 1999 to between 24% and 27% in 2051 and to between 25% and 28% in 2101. The proportion aged 85 years and over is expected to almost quadruple, from 1.3% in 1999 to around 5% in 2051 and around 6% in 2101.

Table 5.13summarises changes from 1901 to 1999, and projections to 2101, in population size, age structure, and proportion living in capital cities.

5.13 POPULATION, Summary Indicators - 1901-2101

Indicator

Units

1901

1947

1971

1999

2021(a)

2051(a)

2101(a)

Total population

'000

3,773.8

7,579.4

13,067.3

18,966.8

22,926.4

25,408.5

25,254.1

Proportion of population aged

- 0-14 years

%

35.1

25.1

28.7

20.7

16.1

14.4

14.4

- 15-64 years

%

60.8

66.8

63.0

67.1

65.5

59.6

58.6

- 65-84 years

%

3.9

7.7

7.8

11.0

16.3

21.0

21.3

- 85+ years

%

0.1

0.4

0.5

1.3

2.1

5.1

5.7

Males per 100 females

no.

110.1

100.4

101.1

99.1

99.2

98.8

99.4

Median age

years

22.5

30.7

27.5

34.9

41.2

46.0

46.1

Proportion living in capital cities

%

36.8

51.2

63.2

63.8

65.4

67.5

n.a.

(a) Series II population projections.

Source: Census of the Commonwealth of Australia, 1911; Australian Demography, 1947; Australian Demographic Statistics (3101.0); Population Projections, Australia 1999 to 2101 (3222.0).